High frequency module and antenna device

ABSTRACT

The present invention includes: a first main waveguide  1 ; a T-branch circuit  3  connected thereto; a first low-pass filter  5  connected thereto; a band-pass filter  7  connected to the first T-branch circuit  3 ; a first converter  8  connected to the first low-pass filter  5  for converting transmission lines between a waveguide and a microwave integrated circuit; an amplifier  10  connected to the first converter and structured by the microwave integrated circuit; a second converter  9  connected thereto for converting transmission lines between a waveguide and the microwave integrated circuit; a second low-pass filter  6  connected thereto; a second T-branch circuit  4  connected to the second low-pass filter and the band-pass filter  7 ; and a second main waveguide  2  connected to the second T-branch circuit.

This application is a 371 of PCT/JP03/03451 filed Mar. 3, 2003.

TECHNICAL FIELD

The present invention relates to a high frequency module that is usedmainly in VHF, UHF, microwave and millimeter wave bands, and moreparticularly to an antenna apparatus using the same.

BACKGROUND ART

FIG. 19 shows an arrangement of an antenna apparatus for shared use ofleft/right-handed circularly polarized waves and two frequency bands setforth, for example, in Takashi Kitsuregawa, “Advanced Technology inSatellite Communication Antennas: Electrical & Mechanical Design”,ARTECH HOUSE INC., pp. 193–195, 1990.

In the figure, reference numeral 61 denotes a primary radiator fortransmitting both left- and right-handed circularly polarized waves in afirst frequency band to a main- or sub-reflector and for receiving bothleft- and right-handed circularly polarized waves in a second frequencyband from the main- or sub-reflector; 62, a polarizer; 63, an orthomodetransducer; 64 a and 64 b, diplexers; P1, an input terminal for radiowaves in the first frequency band transmitted from the primary radiator61 in a left-handed circular polarized wave; P2, an output terminal forradio waves in the second frequency band received by the primaryradiator 61 in a left-handed circular polarized wave; P3, an inputterminal for radio waves in the first frequency band transmitted fromthe primary radiator 61 in a right-handed circular polarized wave; andP4, an output terminal for radio waves in the second frequency bandreceived by the primary radiator 61 in a right-handed circular polarizedwave.

Next, an operation will be described.

Now, a linearly polarized radio wave in the first frequency bandinputted from the input terminal P1 passes through the diplexer 64 a, isinputted to the orthomode transducer 63 and is outputted as a verticallypolarized wave. The vertically polarized wave is then converted by thepolarizer 62 to a left-handed circularly polarized wave, passes throughthe primary radiator 61 and is radiated from the reflector into the air.Furthermore, a left-handed circularly polarized radio wave in the secondfrequency band received by the reflector passes through the primaryradiator 61, is converted by the polarizer 62 to a vertically polarizedwave, and is inputted to the orthomode transducer 63. The radio wave isthen carried to the diplexer 64 a and is extracted from the outputterminal P2 as a linearly polarized wave.

In the meantime, a linearly polarized radio wave in the first frequencyband inputted from the input terminal P3 passes through the diplexer 64b, is inputted to the orthomode transducer 63 and is outputted as ahorizontally polarized wave. The horizontally polarized wave is thenconverted by the polarizer 62 to a right-handed circularly polarizedwave, passes through the primary radiator 61 and is radiated from thereflector into the air. Furthermore, a right-handed circularly polarizedradio wave in the second frequency band received by the reflector passesthrough the primary radiator 61, is converted by the polarizer 62 to ahorizontally polarized wave, and is inputted to the orthomode transducer63. The radio wave is then carried to the diplexer 64 b and is extractedfrom the output terminal P4 as a linearly polarized wave.

Here, the radio waves in the first frequency band inputted from theinput terminals P1 and P3 hardly leak into the output terminals P2 andP4 owing to isolation characteristics of the diplexers 64 a and 64 b.Furthermore, since the radio waves are converted by the orthomodetransducer 63 into polarized waves which are mutually orthogonal, littleinterference occurs between the two radio waves. Accordingly, twotransmission waves using the same frequency band and having both left-and right-handed circular polarized waves will be efficiently radiatedfrom the primary radiator 61.

Moreover, two radio waves using the same frequency band and having bothleft- and right-handed circular polarized waves, received at the primaryradiator 61, are converted into two linearly polarized waves which aremutually orthogonal without any interference therebetween and isolatedby the polarizer 62 and the orthomode transducer 63. Furthermore, eachisolated radio wave hardly leaks into the input terminals P1 and P3owing to the isolation characteristics of the diplexers 64 a and 64 b.Accordingly, two transmission waves using the same frequency band andhaving differently rotating circular polarized waves will be efficientlyoutputted from the terminal 2 and the terminal 4.

In a conventional antenna apparatus, in order to efficiently extract theradio wave received at the reflector and to carry the extracted wave toa receiver connected to the output terminals P2 and P4, it has beennecessary to suppress transmission loss along a path from the primaryradiator 61 to the receiver as small as possible. This has resulted in aproblem in that the primary radiator 61, the polarizer 62, the orthomodetransducer 63, the diplexers 64 a and 64 b and the receiver must belocated in proximity, which restricts flexibility of a configuration ofthose circuits.

Furthermore, in general, for machine-driven scanning of antenna beams,the primary radiator 61, the polarizer 62 and the orthomode transducer63 rotate with the reflector. In this situation, because of theabove-mentioned need for reduction of transmission loss, the diplexers64 a and 64 b and the receiver must also be located at places where theyrotate with the reflector. This has resulted in a problem in that amachine-driven part of the antenna apparatus grows large and heavy, andits rotating mechanism and rotation supporting mechanism grow large andheavy.

DISCLOSURE OF THE INVENTION

The present invention has been made in order to solve the problemsmentioned above. An object of the invention is to obtain a highfrequency module which enables an antenna apparatus to be made compactand lightweight and enhances flexibility of a configuration ofconstituent circuits, and a compact and lightweight antenna apparatus.

A high frequency module according to the present invention includes: afirst main waveguide; a first T-branch circuit connected to the firstmain waveguide; a first low-pass filter connected to the first T-branchcircuit for transmitting a first frequency band and reflecting a secondfrequency band; a band-pass filter connected to the first T-branchcircuit for transmitting the second frequency band and reflecting thefirst frequency band; a first converter connected to the first low-passfilter for converting transmission lines between a waveguide and amicrowave integrated circuit; an amplifier connected to the firstconverter and structured by the microwave integrated circuit; a secondconverter connected to the amplifier for converting transmission linesbetween a waveguide and the microwave integrated circuit; a secondlow-pass filter connected to the second converter for transmitting thefirst frequency band and reflecting the second frequency band; a secondT-branch circuit connected to the second low-pass filter and theband-pass filter; and a second main waveguide connected to the secondT-branch circuit.

A high frequency module according to the present invention includes: afirst main waveguide; a first T-branch circuit connected to the firstmain waveguide; a first low-pass filter connected to the first T-branchcircuit for transmitting a first frequency band and reflecting a secondfrequency band; a first band-pass filter connected to the first T-branchcircuit and having a partially bent longitudinal axis for transmittingthe second frequency band and reflecting the first frequency band; afirst converter connected to the first low-pass filter for convertingtransmission lines between a waveguide and a microwave integratedcircuit; an amplifier connected to the first converter and structured bythe microwave integrated circuit; a second converter connected to theamplifier for converting transmission lines between a waveguide and themicrowave integrated circuit; a second low-pass filter connected to thesecond converter for transmitting the first frequency band andreflecting the second frequency band; a first bend connected to thefirst band-pass filter; a second bend connected to the first bend; asecond band-pass filter connected to the second bend and having apartially bent longitudinal axis for transmitting the second frequencyband and reflecting the first frequency band; a second T-branch circuitconnected to the second low-pass filter and the second band-pass filter;and a second main waveguide connected to the second T-branch circuit.

A high frequency module according to the present invention includes: afirst main waveguide; a first T-branch circuit connected to the firstmain waveguide; a first band-pass filter connected to the first T-branchcircuit for transmitting a first frequency band and reflecting a secondfrequency band; a second band-pass filter connected to the firstT-branch circuit for transmitting the second frequency band andreflecting the first frequency band; a first converter connected to thefirst band-pass filter for converting transmission lines between awaveguide and a microwave integrated circuit; an amplifier connected tothe first converter and structured by the microwave integrated circuitfor converting transmission lines between a waveguide and the microwaveintegrated circuit; a second converter connected to the amplifier; athird band-pass filter connected to the second converter fortransmitting the first frequency band and reflecting the secondfrequency band; a second T-branch circuit connected to the thirdband-pass filter and the second band-pass filter; and a second mainwaveguide connected to the second T-branch circuit.

A high frequency module according to the present invention includes: afirst main waveguide; a first T-branch circuit connected to the firstmain waveguide; a first band-pass filter connected to the first T-branchcircuit for transmitting a first frequency band and reflecting a secondfrequency band; a second band-pass filter connected to the firstT-branch circuit and having a partially bent longitudinal axis fortransmitting the second frequency band and reflecting the firstfrequency band; a first converter connected to the first band-passfilter for converting transmission lines between a waveguide and amicrowave integrated circuit; an amplifier connected to the firstconverter and structured by the microwave integrated circuit; a secondconverter connected to the amplifier for converting transmission linesbetween a waveguide and the microwave integrated circuit; a thirdband-pass filter connected to the second converter for transmitting thefirst frequency band and reflecting the second frequency band; a firstbend connected to the second band-pass filter; a second bend connectedto the first bend; a fourth band-pass filter connected to the secondbend and having a partially bent longitudinal axis for transmitting thesecond frequency band and reflecting the first frequency band; a secondT-branch circuit connected to the third band-pass filter and the fourthband-pass filter; and a second main waveguide connected to the secondT-branch circuit.

Further, the high frequency module includes a one-side corrugatedrectangular waveguide low-pass filter as the waveguide band-pass filter.

Further, the high frequency module includes an inductive iris-coupledrectangular waveguide band-pass filter as the waveguide band-passfilter.

Further, the high frequency module is characterized in that the T-branchcircuit is provided with a matching step at its branch point.

Further, the high frequency module is structured by combining two metalblocks to which the main waveguides, the T-branch circuits, the low-passfilters or the waveguide band-pass filters, the band-pass filter or theband-pass filters each having a partially bent longitudinal axis and thebends, and waveguide portions of the converters are bored.

Further, the high frequency module is characterized in that theamplifier has one metal plate thereon, and in a gap between the metalplate and an outer wall wider face of the amplifier, a one-sidecapacitive iris-coupled rectangular waveguide low-pass filter isprovided, the waveguide inner walls of which include the metal plate andthe outer wall wider face of the amplifier.

Further, the high frequency module is characterized in that theamplifier has one metal plate thereon, and in a gap between the metalplate and an outer wall wider face of the amplifier, a one-sidecorrugated rectangular waveguide low-pass filter is provided, thewaveguide inner walls of which include the metal plate and the outerwall wider face of the amplifier.

An antenna apparatus according to the present invention includes: aprimary radiator; an orthomode transducer connected to the primaryradiator; any one of the above-mentioned first high frequency module,connected to the orthomode transducer; a first diplexer connected to thefirst high frequency module; any one of the above-mentioned second highfrequency module, connected to the orthomode transducer; and a seconddiplexer connected to the second high frequency module.

An antenna apparatus according to the present invention includes: aprimary radiator; a polarizer connected to the primary radiator; anorthomode transducer connected to the polarizer; any one of theabove-mentioned first high frequency module, connected to the orthomodetransducer; a first diplexer connected to the first high frequencymodule; any one of the above-mentioned second high frequency module,connected to the orthomode transducer; and a second diplexer connectedto the second high frequency module.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view showing an arrangement of a high frequency modulein Embodiment 1 of the present invention.

FIG. 2( a) is a side elevation viewed from a direction A of FIG. 1, FIG.2( b) is a side elevation of a low noise amplifier viewed from adirection B of FIG. 1, and FIG. 2( c) is an internal side elevationviewed from a direction C of FIG. 1.

FIG. 3 is a top view showing an arrangement of a high frequency moduleaccording to Embodiment 2 of the present invention.

FIG. 4( a) is a side elevation viewed from a direction A of FIG. 3, FIG.4( b) is a side elevation of a low noise amplifier viewed from adirection B of FIG. 3, and FIG. 4( c) is an internal side elevationviewed from a direction C of FIG. 3.

FIG. 5 is a top view showing an arrangement of a high frequency moduleaccording to Embodiment 3 of the present invention.

FIG. 6( a) is a side elevation viewed from a direction A of FIG. 5, FIG.6( b) is a side elevation of a low noise amplifier viewed from adirection B of FIG. 5, and FIG. 6( c) is a side elevation viewed from adirection C of FIG. 5.

FIG. 7 is a top view showing an arrangement of a high frequency moduleaccording to Embodiment 4 of the present invention.

FIG. 8( a) is a side elevation viewed from a direction A of FIG. 7, FIG.8( b) is a side elevation of a low noise amplifier viewed from adirection B of FIG. 7, and FIG. 8( c) is a side elevation viewed from adirection C of FIG. 7.

FIG. 9 is a top view showing an assembled arrangement of a highfrequency module of the above-described Embodiment 2 of the inventionaccording to Embodiment 5 of the present invention.

FIG. 10( a) is a side elevation viewed from a direction A of FIG. 8,FIG. 10( b) is a side elevation viewed from a direction B of FIG. 8, andFIG. 10( c) is a side elevation viewed from a direction C of FIG. 8.

FIG. 11 is a top view showing an arrangement of a high frequency moduleaccording to Embodiment 6 of the present invention.

FIG. 12( a) is a side elevation viewed from a direction A of FIG. 11,FIG. 12( b) is a side elevation viewed from a direction B of FIG. 11,and FIG. 12( c) is a side elevation viewed from a direction C of FIG.11.

FIG. 13 is a cross sectional view showing an arrangement of a highfrequency module according to Embodiment 7 of the present invention.

FIG. 14( a) is a side elevation viewed from a direction A of FIG. 13,FIG. 14( b) is a side elevation viewed from a direction B of FIG. 13,and FIG. 14( c) is a side elevation viewed from a direction C of FIG.13.

FIG. 15 is a top view showing an arrangement of a high frequency moduleaccording to Embodiment 8 of the present invention.

FIG. 16( a) a side elevation viewed from a direction A of FIG. 15, FIG.16( b) is a side elevation viewed from a direction B of FIG. 15, andFIG. 16( c) is a side elevation viewed from a direction C of FIG. 15.

FIG. 17 is a block diagram showing an arrangement of an antennaapparatus according to Embodiment 9 of the present invention.

FIG. 18 is a block diagram showing an arrangement of an antennaapparatus according to Embodiment 10 of the present invention.

FIG. 19 is a block diagram showing an arrangement of a conventionalantenna apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described below.

Embodiment 1.

FIG. 1 is a top view showing an arrangement of a high frequency modulein Embodiment 1 of the present invention, FIG. 2( a) is a side elevationviewed from a direction A of FIG. 1, FIG. 2( b) is a side elevation of alow noise amplifier viewed from a direction B of FIG. 1, and FIG. 2( c)is an internal side elevation viewed from a direction C of FIG. 1. Inthose figures, reference numeral 1 denotes a rectangular main waveguide(first main waveguide) in which high frequency radio waves areinputted/outputted from an input/output terminal P5 to be describedbelow; 2, a rectangular main waveguide (second main waveguide) in whichhigh frequency radio waves are inputted/outputted from an input/outputterminal P6 to be described below; 3, an E-plane T-branch circuit (firstT-branch circuit) of a stepped rectangular waveguide in which theE-planes of the rectangular waveguide each have a T-shape and its branchportion (branch point) is provided with a matching step; 4, an E-planeT-branch circuit (second T-branch circuit) of a stepped rectangularwaveguide in which the E-planes of the rectangular waveguide each have aT-shape and its branch portion (branch point) is provided with amatching step; 5, a one-side corrugated rectangular waveguide low-passfilter (first low-pass filter) in which one of H-planes of therectangular waveguide that faces a low-pass filter 6 to be describedbelow is corrugated; 6, a one-side corrugated rectangular waveguidelow-pass filter (second low-pass filter) in which one of the H-planes ofthe rectangular waveguide that faces the low-pass filter 5 iscorrugated; 7, an inductive iris-coupled rectangular waveguide band-passfilter in which an iris is formed on inner sides of the E-planes of therectangular waveguide; 8, a rectangular waveguide/MIC converter (firstconverter) for converting a transmission line for high frequency radiowaves from a rectangular waveguide to a MIC (Microwave IntergratedCircuit), or from the MIC to the rectangular waveguide; 9, a rectangularwaveguide/MIC converter (second converter) for converting a transmissionline for high frequency waves from a rectangular waveguide to the MIC,or from the MIC to the rectangular waveguide; 10, a low noise amplifier(amplifier) made of the MIC; P5, an input/output terminal provided atone end of the rectangular main waveguide 1; and P6, an input/outputterminal provided at one end of the rectangular main waveguide 2. Inaddition, the matching step described above is a matching rectangularwaveguide one-side E-plane step which forms a stair-like step on theE-plane in the waveguide.

In addition, the input/output terminal P5 is provided at a first port ofthe E-plane T-branch circuit 3, the band-pass filter 7 is provided at asecond port that faces the first port, and the low-pass filter 5 isprovided at a third port that is branched from the branch portion(branch point) between the first port and the second port. In otherwords, the input/output terminal P5 and the band-pass filter 7 arelocated in a straight line.

Similarly, the input/output terminal P6 is provided at a first port ofthe E-plane T-branch circuit 4, the band-pass filter 7 is provided at asecond port that faces the first port, and the low-pass filter 6 isprovided at a third port that is branched from the branch portion(branch point) between the first port and the second port. In otherwords, the input/output terminal P6 and the band-pass filter 7 arelocated in a straight line.

In addition, the low-pass filters 5 and 6 are designed to transmit radiowaves in a first frequency band and to reflect radio waves in a secondfrequency band which is a higher frequency band than the first frequencyband. Furthermore, the band-pass filter 7 is designed to transmit radiowaves in the second frequency band and to reflect radio waves in thefirst frequency band.

Moreover, the E-plane T-branch circuit 3 is provided, at the branchportion (branch point), with the matching step designed so that areflected wave produced when a radio wave in the first frequency band isincident on the main waveguide 1 side and a reflected wave produced whena radio wave in the second frequency band is incident on the band-passfilter 7 side are reduced, respectively. Furthermore, the E-planeT-branch circuit 4 is provided, at the branch portion (branch point),with the matching step designed so that a reflected wave produced when aradio wave in the first frequency band is incident on the low-passfilter 6 side and a reflected wave produced when a radio wave in thesecond frequency band is incident on the main waveguide 1 side arereduced, respectively.

Next, an operation will be described.

First, when a fundamental mode (rectangular waveguide TE01 mode) of aradio wave in the first frequency band is inputted from the input/outputterminal P5, this radio wave propagates through the main waveguide 1,the E-plane T-branch circuit 3 and the low-pass filter 5 and enters thelow noise amplifier 10 from the converter 8. Then, after the radio waveis amplified in the low noise amplifier 10, the wave exits from theconverter 9, propagates through the low-pass filter 6, the E-planeT-branch circuit 4 and the main waveguide 2 and is outputted from theinput/output terminal P6 as the fundamental mode of the rectangularwaveguide. On the other hand, even if the fundamental mode of the radiowave in the first frequency band is incident from the E-plane T-branchcircuit 3 on the band-pass filter 7, the radio wave is reflected by theband-pass filter 7, and hence does not propagate through the path of theE-plane T-branch circuit 3, the band-pass filter 7 and the E-planeT-branch circuit 3.

Next, suppose a fundamental mode (rectangular waveguide TE01 mode) of aradio wave in the second frequency band, which is a higher frequencyband than the first frequency band, is inputted from the input/outputterminal P6. This radio wave propagates through the main waveguide 2,the E-plane T-branch circuit 4, the band-pass filter 7, the E-planeT-branch circuit 2 and the main waveguide 1, and is outputted from theinput/output terminal P5 as a fundamental mode of the rectangularwaveguide. On the other hand, even if the fundamental mode of the radiowave in the second frequency band is incident from the E-plane T-branchcircuit 4 on the low-pass filter 6, the radio wave is reflected by thelow-pass filter 6, and hence does not propagate through the path of theE-plane T-branch circuit 4, the low-pass filter 6, the converter 9, thelow noise amplifier 10, the converter 8, the low-pass filter 5 and theE-plane T-branch circuit 3.

Therefore, a radio wave in the first frequency band inputted from theinput/output terminal P5 is efficiently inputted to the low noiseamplifier 10 while suppressing reflection to the input/output terminalP5 and direct leakage into the E-plane T-branch circuit 4 side.Moreover, the radio wave in the first frequency band amplified by thelow noise amplifier 10 is efficiently outputted from the input/outputterminal P6 without regressing to the E-plane T-branch circuit 3 side.Furthermore, a radio wave in the second frequency band inputted from theinput/output terminal P5 is efficiently outputted from the input/outputterminal P5 while suppressing reflection to the input/output terminal P6and leakage into the low noise amplifier 10 side.

In this way, according to this Embodiment 1, the rectangular waveguideE-plane T-branch circuit 3 connects to the low-pass filter 5 and theband-pass filter 7, the low-pass filter 5 connects to the rectangularwaveguide/MIC converter 8, the rectangular waveguide/MIC converter 8connects to the low noise amplifier 10, the low noise amplifier 10connects to the rectangular waveguide/MIC converter 9, the rectangularwaveguide/MIC converter 9 connects to the low-pass filter 6, and thelow-pass filter 6 and the band-pass filter 7 connect to the rectangularwaveguide E-plane T-branch circuit 4. This provides an effect in thatradio waves in the first frequency band inputted from the input/outputterminal P5 can be efficiently amplified and passed without causingoscillation, and that, at the same time, radio waves in the secondfrequency band inputted from the input/output terminal P6 can be passedwith little loss.

Further, if the number of resonator stages of the band-pass filter 7 isdecreased as appropriate, a distance between the input/output terminalP5 and the input/output terminal P6 is reduced. This provides an effectof being capable of obtaining a high frequency module which can be madecompact and lightweight and which has high performance.

Embodiment 2.

FIG. 3 is a top view showing an arrangement of a high frequency moduleaccording to Embodiment 2 of the present invention, FIG. 4( a) is a sideelevation viewed from a direction A of FIG. 3, FIG. 4( b) is a sideelevation of a low noise amplifier viewed from a direction B of FIG. 3,and FIG. 4( c) is an internal side elevation viewed from a direction Cof FIG. 3.

In Embodiment 1 described above, the band-pass filter 7 isillustratively connected to the rectangular waveguide E-plane T-branchcircuits 3 and 4. As shown in FIG. 3, however, the band-pass filter 7 isreplaced by an inductive iris-coupled rectangular waveguide band-passfilter 11 (first band-pass filter) which is connected to the E-planeT-branch circuit 3 and which has a partially bent longitudinal axis, arectangular waveguide E-plane bend 13 (first bend) connected to theband-pass filter 11, a rectangular waveguide E-plane bend 14 (secondbend) connected to the rectangular waveguide E-plane bend 13, and aninductive iris-coupled rectangular waveguide band-pass filter 12 (secondband-pass filter) which is connected to the rectangular waveguideE-plane bend 14 and which has a partially bent longitudinal axis. Notethat, an operation is not described because the operation is similar tothat of Embodiment 1.

In this way, since the high frequency module in this embodiment isarranged as described above, the high frequency module provides aneffect similar to that of Embodiment 1.

Furthermore, if the number of resonator stages constituting theband-pass filters 11 and 12 is increased in an upward direction of FIG.3, that is, in a direction in which the low noise amplifier 10 isplaced, then an effect is provided in that the amount of radio waves inthe first frequency band that directly leaks from the E-plane T-branchcircuit 3 into the E-plane T-branch circuit 4 can be significantlyreduced without changing a distance between the input/output terminal P5and the input/output terminal P6.

Moreover, by appropriately determining a distance between the band-passfilters 11, 12 and the E-plane bends 13, 14, another effect is providedin that a superior reflection characteristic can be obtained in thesecond frequency band without changing the distance between theinput/output terminal P5 and the input/output terminal P6. There isstill another effect of increasing design flexibility.

Embodiment 3.

FIG. 5 is a top view showing an arrangement of a high frequency moduleaccording to Embodiment 3 of the present invention, FIG. 6( a) is a sideelevation viewed from a direction A of FIG. 1, FIG. 6( b) is a sideelevation of a low noise amplifier viewed from a direction B of FIG. 5,and FIG. 6( c) is a side elevation viewed from a direction C of FIG. 5.In Embodiment 1 described above, the low-pass filters 5 and 6 areillustratively connected to the rectangular waveguide E-plane T-branchcircuits 3 and 4. As shown in FIG. 5, however, the low-pass filters 5and 6 are replaced by inductive iris-coupled rectangular waveguideband-pass filters 15 and 16 (first band-pass filter and third band-passfilter). Note that the band-pass filter 7 corresponds to the secondband-pass filter.

Here, the inductive iris-coupled rectangular waveguide band-pass filters15 and 16 used in Embodiment 3 each have a structure similar to that ofthe inductive iris-coupled rectangular waveguide band-pass filter 7 usedin Embodiment 1.

Note that, an operation is not described because the operation issimilar to that of Embodiment 1.

In this way, since the high frequency module in this embodiment isarranged as described above, the high frequency module provides aneffect similar to that of Embodiment 1. Moreover, even if a spacingbetween the first frequency band and the second frequency band isnarrow, an effect is provided in that the amount of radio waves in thesecond frequency band that leaks into the low noise amplifier 10 sidecan be significantly reduced.

Embodiment 4.

FIG. 7 is a top view showing an arrangement of a high frequency moduleaccording to Embodiment 4 of the present invention, FIG. 8( a) is a sideelevation viewed from a direction A of FIG. 7, FIG. 8( b) is a sideelevation of a low noise amplifier viewed from a direction B of FIG. 7,and FIG. 8( c) is a side elevation viewed from a direction C of FIG. 7.In Embodiment 1 described above, the low-pass filters 5 and 6 and theband-pass filter 7 are illustratively connected to the rectangularwaveguide E-plane T-branch circuits 3 and 4. As shown in FIG. 7,however, the low-pass filters 5 and 6 are replaced by the inductiveiris-coupled rectangular waveguide band-pass filters 15 and 16 (firstband-pass filter and third band-pass filter). In addition, the band-passfilter 7 is replaced by an inductive iris-coupled rectangular waveguideband-pass filter 11 (second band-pass filter) which is connected to theE-plane T-branch circuit 3 and which has a partially bent longitudinalaxis, a rectangular waveguide E-plane bend 13 connected to the band-passfilter 11, a rectangular waveguide E-plane bend 14 connected to therectangular waveguide E-plane bend 13, and an inductive iris-coupledrectangular waveguide band-pass filter 12 (fourth band-pass filter)which is connected to the rectangular waveguide E-plane bend 14 andwhich has a partially bent longitudinal axis.

In this way, since the high frequency module in this embodiment isarranged as described above, the high frequency module provides aneffect similar to that of Embodiment 1. Moreover, even if the spacingbetween the first frequency band and the second frequency band isnarrow, an effect is provided in that the amount of radio waves in thesecond frequency band that leaks into the low noise amplifier 10 sidecan be significantly reduced.

Furthermore, if the number of resonator stages constituting theband-pass filters 11 and 12 is increased in an upward direction of FIG.7, that is, in a direction in which the low noise amplifier 10 isplaced, then an effect is provided in that the amount of radio waves inthe first frequency band that directly leaks from the E-plane T-branchcircuit 3 into the E-plane T-branch circuit 4 can be significantlyreduced without changing the distance between the input/output terminalP5 and the input/output terminal P6.

Moreover, by appropriately determining the distance between theband-pass filters 11, 12 and the E-plane bends 13, 14, another effect isprovided in that a superior reflection characteristic can be obtained inthe second frequency band without changing the distance between theinput/output terminal P5 and the input/output terminal P6.

Embodiment 5.

FIG. 9 is a top view showing an assembled arrangement of the highfrequency module of the above-described Embodiment 2 of the inventionaccording to Embodiment 5 of the present invention, FIG. 10( a) is aside elevation viewed from a direction A of FIG. 8, FIG. 10( b) is aside elevation viewed from a direction B of FIG. 8, and FIG. 10( c) is aside elevation viewed from a direction C of FIG. 8. In those figures,reference numeral 17 denotes a bisected waveguide metal block realizedin an integral structure by boring one metal block to form upperportions of E-plane symmetric partitions of the main waveguides 1 and 2,the T-branch circuits 3 and 4, the low-pass filters 5 and 6, thewaveguide portions of the waveguide/MIC converters 8 and 9, theband-pass filters 11 and 12, and the waveguide bends 13 and 14; 18, abisected waveguide metal block realized in an integral structure byboring one metal block to form lower portions of E-plane symmetricpartitions of the main waveguides 1 and 2, the T-branch circuits 3 and4, the low-pass filters 5 and 6, the waveguide portions of thewaveguide/MIC converters 8 and 9, the band-pass filters 11 and 12, andthe waveguide bends 13 and 14; 19, a metal plate for locating andsupporting the low noise amplifier 10 in the metal blocks 17 and 18.

Note that, an operation is not described because the operation issimilar to that of Embodiment 2.

In this way, according to this Embodiment 5, the high frequency moduleis arranged by combining the metal blocks 17 and 18, each integrallyforming the main waveguides 1 and 2, the T-branch circuits 3 and 4, thelow-pass filters 5 and 6, the waveguide portions of the waveguide/MICconverters 8 and 9, the band-pass filters 11 and 12, and the waveguidebends 13 and 14. This provides an effect, in addition to the effect ofEmbodiment 2, in that connection supporting mechanisms such as flanges,usually needed to interconnect waveguide circuits, are significantlyreduced, which enables a more compact and lightweight, andhigh-performance high frequency module to be obtained.

Embodiment 6.

FIG. 11 is a top view showing an arrangement of a high frequency moduleaccording to Embodiment 6 of the present invention, FIG. 12( a) is aside elevation viewed from a direction A of FIG. 11, FIG. 12( b) is aside elevation viewed from a direction B of FIG. 11, and FIG. 12( c) isa side elevation viewed from a direction C of FIG. 11. In Embodiment 5described above, wider faces of the low noise amplifier 10 areillustratively grounded on combining faces of the metal blocks 17 and18. In this embodiment, however, as shown in FIG. 11, narrower faces ofthe low noise amplifier 10 are placed on the combining faces of themetal blocks 17 and 18.

Note that, an operation is not described because the operation issimilar to that of Embodiment 2.

In this way, since the high frequency module in this embodiment isarranged as described above, the high frequency module provides aneffect, similar to that of Embodiment 5, in that connection supportingmechanisms such as flanges, usually needed to interconnect waveguidecircuits, are significantly reduced, which enables a more compact andlightweight, and high-performance high frequency module to be obtained.

Embodiment 7.

FIG. 13 is a cross sectional view showing an arrangement of a highfrequency module according to Embodiment 7 of the present invention,FIG. 14( a) is a side elevation viewed from a direction A of FIG. 13,FIG. 14( b) is a side elevation viewed from a direction B of FIG. 13,and FIG. 14( c) is a side elevation viewed from a direction C of FIG.13. In Embodiment 5 described above, the metal plate 19 for support isprovided on the low noise amplifier 10. Usually, however, between anouter wall wider face of the low noise amplifier 10 and the ground faceof the metal plate 19, a gap may be made which is inevitable inassembly. In this case, since some artificial waveguide modes aretransmitted in this gap, an unwanted coupling is excited between thewaveguide/MIC converters 8 and 9, which results in degradation ofcharacteristics.

In this embodiment, as shown in FIG. 13, a gap is deliberately providedbetween the outer wall wider face of the low noise amplifier 10 and aground face of a metal plate 20, and a one-side capacitive iris-coupledrectangular waveguide band-pass filter 21 is provided, the waveguidewider faces of which include the outer wall wider faces of theabove-described metal plate and the above-described low noise amplifier.

Note that, an operation is not described because the operation issimilar to that of Embodiment 2.

In this way, since the high frequency module in this embodiment isarranged as described above, the high frequency module provides aneffect, in addition to that of Embodiment 5, in that the above-describedunwanted coupling is suppressed and the degradation of characteristicscan be avoided.

Embodiment 8

FIG. 15 is a top view showing an arrangement of a high frequency moduleaccording to Embodiment 8 of the present invention, FIG. 16( a) is aside elevation viewed from a direction A of FIG. 15, FIG. 16( b) is aside elevation viewed from a direction B of FIG. 15, and FIG. 16( c) isa side elevation viewed from a direction C of FIG. 15. In Embodiment 7described above, the gap is provided between the outer wall wider faceof the low noise amplifier 10 and the ground face of the metal plate 20,where a waveguide band-pass filter 23 is provided. As shown in FIG. 8,however, a gap is provided between the outer wall wider face of the lownoise amplifier 10 and a ground face of a metal plate 22, where aone-side corrugated rectangular waveguide low-pass filter 23 is placed.

Note that, an operation is not described because the operation issimilar to that of Embodiment 2.

In this way, since the high frequency module in this embodiment isarranged as described above, an effect similar to that of Embodiment 7is achieved.

Embodiment 9.

FIG. 17 is a block diagram showing an arrangement of an antennaapparatus according to Embodiment 9 of the present invention. In thefigure, reference numeral 24 denotes a primary radiator for transmittingboth vertical and horizontal linearly polarized waves in a firstfrequency band to a main- or sub-reflector and for receiving bothvertical and horizontal linearly polarized waves in a second frequencyband from the main- or sub-reflector; 25, an orthomode transducer; 26 a,a high frequency module in the above-described Embodiment 5 connected tothe orthomode transducer 24; 26 b, a high frequency module in theabove-described Embodiment 5 connected to the orthomode transducer 24;27 a, a diplexer described below; P1, an input terminal for radio wavesin the first frequency band transmitted from the primary radiator 24 ina vertically polarized wave; P2, an output terminal for radio waves inthe second frequency band received by the primary radiator 24 in avertically polarized wave; P3, an input terminal for radio waves in thefirst frequency band transmitted from the primary radiator 24 in ahorizontally polarized wave; and P4, an output terminal for radio wavesin the second frequency band received by the primary radiator 24 in ahorizontally polarized wave.

Next, an operation will be described.

First, a linearly polarized radio wave in the first frequency bandinputted from the input terminal P1 passes through the diplexer 27 a andthe high frequency module 26 a, is inputted to the orthomode transducer25, and is outputted as a vertically polarized wave. The verticallypolarized wave then passes through the primary radiator 24 and isradiated from the reflector into the air.

Furthermore, a vertically polarized radio wave in the second frequencyband received by the reflector passes through the primary radiator 24and is inputted to the orthomode transducer 25. The radio wave is thenamplified by the high frequency module 26 a, is carried to the diplexer27 a, and is extracted from the output terminal P2 as a linearlypolarized wave.

Next, a linearly polarized radio wave in the first frequency bandinputted from the input terminal P3 passes through the diplexer 27 b andthe high frequency module 26 b, is inputted to the orthomode transducer25, and is outputted as a horizontally polarized wave. The horizontallypolarized wave then passes through the primary radiator 24 and isradiated from the reflector into the air.

Furthermore, a horizontally polarized radio wave in the second frequencyband received by the reflector passes through the primary radiator 24and is inputted to the orthomode transducer 25. The radio wave is thenamplified by the high frequency module 26 b, is carried to the diplexer27 b, and is extracted from the output terminal P4 as a linearlypolarized wave.

Here, the radio waves in the first frequency band inputted from theinput terminal P1 and the input terminal P3 hardly leak into the outputterminal P2 and the output terminal P4 owing to isolationcharacteristics of the diplexers 27 a and 27 b. Furthermore, since theradio waves are converted by the orthomode transducer 25 into polarizedwaves which are mutually orthogonal, little interference occurs betweenthe two radio waves. Accordingly, two transmission waves using the samefrequency band and having both vertical and horizontal polarized waveswill be efficiently radiated from the primary radiator 24.

Furthermore, two radio waves using the same frequency band and havingboth vertical and horizontal polarized waves, received by the primaryradiator 24, are isolated by the orthomode transducer 25 without anyinterference therebetween. Furthermore, each isolated radio wave hardlyleaks into the input terminal P1 and the input terminal P3 owing to theisolation characteristics of the diplexers 27 a and 27 b. Accordingly,two transmission waves using the same frequency band and havingdifferently rotating circular polarized waves will be efficientlyoutputted from the output terminal 2 and the output terminal 4.

In this way, according to this Embodiment 9, a radio wave received atthe reflector is amplified once in the high frequency modules 26 a and26 b while the radio wave is carried to a receiver connected to theoutput terminal P2 and the output terminal P4. This eliminates the needto locate the orthomode transducer 25, the diplexers 27 a and 27 b, andthe receiver in proximity, which results in an effect in thatflexibility of the configuration of those circuits is enhanced.Furthermore, when machine-driven manipulation of antenna beams isperformed, it is not necessary to locate the diplexers 27 a and 27 b andthe receiver at places where they rotate with the reflector. Thisprovides an effect of being capable of obtaining an antenna apparatuswhose rotating mechanism and rotation supporting mechanism can be madecompact and lightweight and which has high performance.

Embodiment 10.

FIG. 18 is a block diagram showing an arrangement of an antennaapparatus according to Embodiment 10 of the present invention. In thefigure, reference numeral 24 denotes a primary radiator for transmittingboth left- and right-handed circularly polarized waves in a firstfrequency band to a main- or sub-reflector and for receiving both left-and right-handed circularly polarized waves in a second frequency bandfrom the main- or sub-reflector; 25, an orthomode transducer connectedto a polarizer 28 to be described below; 26 a, a high frequency modulein the above-described Embodiment 5 connected to the orthomodetransducer 25; 26 b, a high frequency module in the above-describedEmbodiment 5 connected to the orthomode transducer 25; 27 a, a diplexerconnected to the high frequency module 26 a; 27 b, a diplexer connectedto the high frequency module 26 b; 28, a polarizer provided between theprimary radiator 24 and the orthomode transducer 25; P1, an inputterminal, connected to the diplexer 27 a, for radio waves in the firstfrequency band transmitted from the primary radiator 24 in a left-handedcircular polarized wave; P2, an output terminal, connected to thediplexer 27 a, for radio waves in the second frequency band receivedfrom the primary radiator 24 in a left-handed circular polarized wave;P3, an input terminal, connected to the diplexer 27 b, for radio wavesin the first frequency band transmitted from the primary radiator 24 ina right-handed circular polarized wave; and P4, an input terminal,connected to the diplexer 27 b, for radio waves in the second frequencyband received from the primary radiator 24 in a right-handed circularpolarized wave.

Next, an operation will be described.

First, a linearly polarized radio wave in the first frequency bandinputted from the input terminal P1 passes through the diplexer 27 a andthe high frequency module 26 a, is inputted to the orthomode transducer25, and is outputted as a vertically polarized wave. The verticallypolarized wave is then converted by the polarizer 28 to a left-handedcircularly polarized wave, passes through the primary radiator 24, andis radiated from the reflector into the air.

Furthermore, a left-handed circularly polarized radio wave in the secondfrequency band received by the reflector passes through the primaryradiator 24, is converted by the polarizer 28 to a vertically polarizedwave, and is inputted to the orthomode transducer 25. The radio wave isthen amplified by the high frequency module 26 a, is carried to thediplexer 27 a, and is extracted from the output terminal P2 as alinearly polarized wave.

Next, a linearly polarized radio wave in the first frequency bandinputted from the input terminal P3 passes through the diplexer 27 b andthe high frequency module 26 b, is inputted to the orthomode transducer25, and is outputted as a horizontally polarized wave. The horizontallypolarized wave is then converted by the polarizer 28 to a right-handedcircularly polarized wave, passes through the primary radiator 24, andis radiated from the reflector into the air.

Furthermore, a right-handed circularly polarized radio wave in thesecond frequency band received by the reflector passes through theprimary radiator 24, is converted by the polarizer 28 from theright-handed circularly polarized wave to a horizontally polarized wave,and is inputted to the orthomode transducer 25. The horizontallypolarized wave is then amplified by the high frequency module 26 b, iscarried to the diplexer 27 b, and is extracted from the output terminalP4 as a linearly polarized wave.

Here, the radio waves in the first frequency band inputted from theinput terminal P1 and the input terminal P3 hardly leak into the outputterminal P2 and the output terminal P4 owing to isolationcharacteristics of the diplexers 27 a and 27 b. Furthermore, since theradio waves are converted by the orthomode transducer 25 into polarizedwaves which are mutually orthogonal, little interference occurs betweenthe two radio waves. Accordingly, two transmission waves using the samefrequency band and having both left- and right-handed circular polarizedwaves will be efficiently radiated from the primary radiator 24.

Further, two radio waves using the same frequency band and having bothleft- and right-handed circular polarized waves, received by the primaryradiator 24, are converted into two linearly polarized waves which aremutually orthogonal without any interference therebetween and isolatedby the polarizer 28 and the orthomode transducer 25. Furthermore, eachisolated radio wave hardly leaks into the output terminal P1 and theoutput terminal P3 owing to the isolation characteristics of thediplexers 27 a and 27 b. Accordingly, two transmission waves using thesame frequency band and having differently rotating circular polarizedwaves will be efficiently outputted from the output terminal 2 and theoutput terminal 4.

In this way, according to this Embodiment 10, a radio wave received atthe reflector is amplified once in the high frequency modules 26 a and26 b while the radio wave is carried to a receiver connected to theoutput terminal P2 and the output terminal P4. This eliminates the needto locate the orthomode transducer 25, the diplexers 27 a and 27 b, andthe receiver in proximity, which results in an effect in thatflexibility of the configuration of those circuits is enhanced.Furthermore, when machine-driven manipulation of antenna beams isperformed, it is not necessary to locate the diplexers 27 a and 27 b andthe receiver at places where they rotate with the reflector. Thisprovides an effect of being capable of obtaining an antenna apparatuswhose rotating mechanism and rotation supporting mechanism can be madecompact and lightweight and which has high performance.

Hereinafter, effects of the present invention are described.

A high frequency module according to the present invention includes: afirst main waveguide; a first T-branch circuit connected to the firstmain waveguide; a first low-pass filter connected to the first T-branchcircuit for transmitting a first frequency band and reflecting a secondfrequency band; a band-pass filter connected to the first T-branchcircuit for transmitting the second frequency band and reflecting thefirst frequency band; a first converter connected to the first low-passfilter for converting transmission lines between a waveguide and amicrowave integrated circuit; an amplifier connected to the firstconverter and structured by the microwave integrated circuit; a secondconverter connected to the amplifier for converting transmission linesbetween a waveguide and the microwave integrated circuit; a secondlow-pass filter connected to the second converter for transmitting thefirst frequency band and reflecting the second frequency band; a secondT-branch circuit connected to the second low-pass filter and theband-pass filter; and a second main waveguide connected to the secondT-branch circuit. Accordingly, the effect can be obtained in which aradio wave in the first frequency band can be amplified and passedeffectively without being oscillated, and a radio wave in the secondfrequency band input opposing to the radio wave in the first frequencyband can be passed with little loss.

A high frequency module according to the present invention includes: afirst main waveguide; a first T-branch circuit connected to the firstmain waveguide; a first low-pass filter connected to the first T-branchcircuit for transmitting a first frequency band and reflecting a secondfrequency band; a first band-pass filter connected to the first T-branchcircuit and having a partially bent longitudinal axis for transmittingthe second frequency band and reflecting the first frequency band; afirst converter connected to the first low-pass filter for convertingtransmission lines between a waveguide and a microwave integratedcircuit; an amplifier connected to the first converter and structured bythe microwave integrated circuit; a second converter connected to theamplifier for converting transmission lines between a waveguide and themicrowave integrated circuit; a second low-pass filter connected to thesecond converter for transmitting the first frequency band andreflecting the second frequency band; a first bend connected to thefirst band-pass filter; a second bend connected to the first bend; asecond band-pass filter connected to the second bend and having apartially bent longitudinal axis for transmitting the second frequencyband and reflecting the first frequency band; a second T-branch circuitconnected to the second low-pass filter and the second band-pass filter;and a second main waveguide connected to the second T-branch circuit.Accordingly, the effect can be obtained in which a radio wave in thefirst frequency band can be amplified and passed effectively withoutbeing oscillated, and a radio wave in the second frequency band inputopposing to the radio wave in the first frequency band can be passedwith little loss.

A high frequency module according to the present invention includes: afirst main waveguide; a first T-branch circuit connected to the firstmain waveguide; a first band-pass filter connected to the first T-branchcircuit for transmitting a first frequency band and reflecting a secondfrequency band; a second band-pass filter connected to the firstT-branch circuit for transmitting the second frequency band andreflecting the first frequency band; a first converter connected to thefirst band-pass filter for converting transmission lines between awaveguide and a microwave integrated circuit; an amplifier connected tothe first converter and structured by the microwave integrated circuitfor converting transmission lines between a waveguide and the microwaveintegrated circuit; a second converter connected to the amplifier; athird band-pass filter connected to the second converter fortransmitting the first frequency band and reflecting the secondfrequency band; a second T-branch circuit connected to the thirdband-pass filter and the second band-pass filter; and a second mainwaveguide connected to the second T-branch circuit. Accordingly, theeffect can be obtained in which a radio wave in the first frequency bandcan be amplified and passed effectively without being oscillated, and aradio wave in the second frequency band input opposing to the radio wavein the first frequency band can be passed with little loss.

A high frequency module according to the present invention includes: afirst main waveguide; a first T-branch circuit connected to the firstmain waveguide; a first band-pass filter connected to the first T-branchcircuit for transmitting a first frequency band and reflecting a secondfrequency band; a second band-pass filter connected to the firstT-branch circuit and having a partially bent longitudinal axis fortransmitting the second frequency band and reflecting the firstfrequency band; a first converter connected to the first band-passfilter for converting transmission lines between a waveguide and amicrowave integrated circuit; an amplifier connected to the firstconverter and structured by the microwave integrated circuit; a secondconverter connected to the amplifier for converting transmission linesbetween a waveguide and the microwave integrated circuit; a thirdband-pass filter connected to the second converter for transmitting thefirst frequency band and reflecting the second frequency band; a firstbend connected to the second band-pass filter; a second bend connectedto the first bend; a fourth band-pass filter connected to the secondbend and having a partially bent longitudinal axis for transmitting thesecond frequency band and reflecting the first frequency band; a secondT-branch circuit connected to the third band-pass filter and the fourthband-pass filter; and a second main waveguide connected to the secondT-branch circuit. Accordingly, the effect can be obtained in which aradio wave in the first frequency band can be amplified and passedeffectively without being oscillated, and a radio wave in the secondfrequency band input opposing to the radio wave in the first frequencyband can be passed with little loss.

Further, the high frequency module includes a one-side corrugatedrectangular waveguide low-pass filter as the waveguide band-pass filter.Accordingly, the effect can be obtained in which a radio wave in thefirst frequency band can be amplified and passed effectively withoutbeing oscillated, and a radio wave in the second frequency band inputopposing to the radio wave in the first frequency band can be passedwith little loss.

Further, the high frequency module includes an inductive iris-coupledrectangular waveguide band-pass filter as the waveguide band-passfilter. Accordingly, the effect can be obtained in which a radio wave inthe first frequency band can be amplified and passed effectively withoutbeing oscillated, and a radio wave in the second frequency band inputopposing to the radio wave in the first frequency band can be passedwith little loss.

Further, the high frequency module is characterized in that the T-branchcircuit is provided with a matching step at its branch point.Accordingly, radio waves in the first and second frequency bands can beinput and output effectively.

Further, the high frequency module is structured by combining two metalblocks to which the main waveguides, the T-branch circuits, the low-passfilters or the waveguide band-pass filters, the band-pass filter or theband-pass filters each having a partially bent longitudinal axis and thebends, and waveguide portions of the converters are bored. Accordingly,a connect supporting mechanism for each component can be reduced.

Further, the high frequency module is characterized in that theamplifier has one metal plate thereon, and in a gap between the metalplate and an outer wall wider face of the amplifier, a one-sidecapacitive iris-coupled rectangular waveguide low-pass filter isprovided, the waveguide inner walls of which include the metal plate andthe outer wall wider face of the amplifier. Accordingly, unwantedconnection can be restrained.

Further, the high frequency module is characterized in that theamplifier has one metal plate thereon, and in a gap between the metalplate and an outer wall wider face of the amplifier, a one-sidecorrugated rectangular waveguide low-pass filter is provided, thewaveguide inner walls of which include the metal plate and the outerwallwider face of the amplifier. Accordingly, unwanted connection can berestrained.

An antenna apparatus according to the present invention includes: aprimary radiator; an orthomode transducer connected to the primaryradiator; any one of the above-mentioned first high frequency module,connected to the orthomode transducer; a first diplexer connected to thefirst high frequency module; any one of the above-mentioned second highfrequency module, connected to the orthomode transducer; and a seconddiplexer connected to the second high frequency module. Therefore, thepresent invention can make the apparatus compact and lightweight.

An antenna apparatus according to the present invention includes: aprimary radiator; a polarizer connected to the primary radiator; anorthomode transducer connected to the polarizer; any one of theabove-mentioned first high frequency module, connected to the orthomodetransducer; a first diplexer connected to the first high frequencymodule; any one of the above-mentioned second high frequency module,connected to the orthomode transducer; and a second diplexer connectedto the second high frequency module. Therefore, the present inventioncan make the apparatus compact and light weight.

INDUSTRIAL APPLICABILITY

As described above, the high frequency module according to the presentinvention is useful as a waveguide diplexer and a low noise amplifierprovided to an antenna. The antenna apparatus according to the presentinvention is useful as a signal transceiver in radio communication forVHF, UHF, microwave, and millimeter wave bands.

1. A high frequency module, characterized by comprising: a first mainwaveguide; a first T-branch circuit connected to the first mainwaveguide; a first low-pass filter connected to the first T-branchcircuit for transmitting a first frequency band and reflecting a secondfrequency band; a band-pass filter connected to the first T-branchcircuit for transmitting the second frequency band and reflecting thefirst frequency band; a first converter connected to the first low-passfilter for converting transmission lines between a waveguide and amicrowave integrated circuit; an amplifier connected to the firstconverter and structured by the microwave integrated circuit; a secondconverter connected to the amplifier for converting transmission linesbetween a waveguide and the microwave integrated circuit; a secondlow-pass filter connected to the second converter for transmitting thefirst frequency band and reflecting the second frequency band; a secondT-branch circuit connected to the second low-pass filter and theband-pass filter; and a second main waveguide connected to the secondT-branch circuit.
 2. A high frequency module according to claim 1,characterized in that the band-pass filter comprises a first band-passfilter connected to the first T-branch circuit and having a partiallybent longitudinal axis for transmitting the second frequency band andreflecting the first frequency band, characterized by furthercomprising: a first bend connected to the first band-pass filter; asecond bend connected to the first bend; a second band-pass filterconnected to the second bend and having a partially bent longitudinalaxis for transmitting the second frequency band and reflecting the firstfrequency band, characterized in that the second T-branch circuitconnected to the second low-pass filter and the second band-pass filter.3. A high frequency module according to claim 1, characterized byfurther comprising a one-side corrugated rectangular waveguide low-passfilter as the low-pass filter.
 4. A high frequency module according toclaim 1, characterized by further comprising an inductive iris-coupledrectangular waveguide band-pass filter as the band-pass filter.
 5. Ahigh frequency module according to claim 1, characterized in that theT-branch circuit is provided with a matching step at its branch point.6. A high frequency module according to claim 1, characterized by beingstructured by combining two metal blocks to which the main waveguides,the T-branch circuits, the low-pass filters or the band-pass filters,the band-pass filter or the band-pass filters each having a partiallybent longitudinal axis and the bends, and waveguide portions of theconverters are bored.
 7. A high frequency module according to claim 6,characterized in that the amplifier has one metal plate thereon, and ina gap between the metal plate and an outer wall wider face of theamplifier, a one-side capacitive iris-coupled rectangular waveguidelow-pass filter is provided, the waveguide inner walls of which comprisethe metal plate and the outer wall wider face of the amplifier.
 8. Ahigh frequency module according to claim 6, characterized in that theamplifier has one metal plate thereon, and in a gap between the metalplate and an outer wall wider face of the amplifier, a one-sidecorrugated rectangular waveguide low-pass filter is provided, thewaveguide inner walls of which comprise the outer wall wider face of themetal plate and the amplifier.
 9. A high frequency module, characterizedby comprising: a first main waveguide; a first T-branch circuitconnected to the first main waveguide; a first band-pass filterconnected to the first T-branch circuit for transmitting a firstfrequency band and reflecting a second frequency band; a secondband-pass filter connected to the first T-branch circuit fortransmitting the second frequency band and reflecting the firstfrequency band; a first converter connected to the first band-passfilter for converting transmission lines between a waveguide and amicrowave integrated circuit; an amplifier connected to the firstconverter and structured by the microwave integrated circuit forconverting transmission lines between a waveguide and the microwaveintegrated circuit; a second converter connected to the amplifier; athird band-pass filter connected to the second converter fortransmitting the first frequency band and reflecting the secondfrequency band; a second T-branch circuit connected to the thirdband-pass filter and the second band-pass filter; and a second mainwaveguide connected to the second T-branch circuit.
 10. A high frequencymodule, characterized by comprising: a first main waveguide; a firstT-branch circuit connected to the first main waveguide; a firstband-pass filter connected to the first T-branch circuit fortransmitting a first frequency band and reflecting a second frequencyband; a second band-pass filter connected to the first T-branch circuitand having a partially bent longitudinal axis for transmitting thesecond frequency band and reflecting the first frequency band; a firstconverter connected to the first band-pass filter for convertingtransmission lines between a waveguide and a microwave integratedcircuit; an amplifier connected to the first converter and structured bythe microwave integrated circuit; a second converter connected to theamplifier for converting transmission lines between a waveguide and themicrowave integrated circuit; a third band-pass filter connected to thesecond converter for transmitting the first frequency band andreflecting the second frequency band; a first bend connected to thesecond band-pass filter; a second bend connected to the first bend; afourth band-pass filter connected to the second bend and having apartially bent longitudinal axis for transmitting the second frequencyband and reflecting the first frequency band; a second T-branch circuitconnected to the third band-pass filter and the fourth band-pass filter;and a second main waveguide connected to the second T-branch circuit.